Someone tell the Scooby gang to fire up the Mystery Machine, because a case may need solving. Seems the Twi-Hards worked themselves into a lather on Monday after photos surfaced that purported to show Kristen Stewart rendezvousing in Los Angeles with her "Snow White and the Huntsman" director Rupert Sanders, he of that caught-on-camera, Mini Cooper-based "momentary indiscretion" from last summer.

The meet-up allegedly took place on Sunday at a Mexican restaurant that Kristen frequents with still-on boyfriend Robert Pattinson, who jetted out of town over the weekend. In grainy photos snapped outside the eatery, a bespectacled K. Stew is seen heading toward a car that sort of resembles one Sanders drives, with a guy who kinda sort of has his basic coloring.

But Stewart insiders are adamant that she did not meet up with the filmmaker, whose marriage to Liberty Ross, a model and mother of his two kids, went belly-up in the wake of the cheating scandal.

According to Gossip Cop, that's not Sanders in the pictures , which were actually taken on Friday (meaning Pattison was still in town). The actress dined with a group of friends, including a few of Rob's. Hollywood Life, meanwhile, says the dark-haired guy in question was simply a restaurant staffer.

"That man is a driver, a valet driver," maintains a source. "After he drove the car to the front of the parking area, he got out and the two young women in the photo got into the car. That young girl wearing glasses, Kristen Stewart, got into the passenger's side. She is a regular here and very friendly."

On April 9, Pattinson tossed a surprise party for Stewart's 23rd birthday at the restaurant, inviting 40 or so pals to join them. A few days later, the "Twilight" twosome surfaced hand-in-hand at the Coachella Music Festival.

A Kristen insider chimes in that there's no "chance in hell she was with Rupert," with another concurring before adding, "That ship and mistake has sailed."